Irish surnames have eclipsed traditional first names as baby names, especially for girls. Irish surnames such as Riley, Kennedy, and Finley are more popular baby names in the US today than traditional Irish names such as Bridget and Patrick. Riley is the top Irish name of any kind of baby girls in the US today, with Ryan the top Irish surname used as a first name for boys. Along with Riley and Ryan, the other top Irish surname names used as first names in the US are Connor and Nolan for boys, Kennedy and Quinn for girls. One fresh factor in Irish surnames for babies: Names that start with Mac or O' are now fair game as first names. So if you want to name your baby O'Brien or McNamara, go right ahead. Here's a whole group of rollicking Irish surnames that work for both girls and boys....or you can use one from your own family background. To explore Irish name options beyond surnames, click here for our full list of Irish baby names.